The objective of this work is to evaluate potential therapeutic interventions in sickle cell anemia patients. It is generally felt that increasing blood oxygen affinity will lead to decreased sickling because a larger fraction of hemoglobin will be in the oxy-configuration at a given partial pressure of oxygen. We have developed methods for the measurement of whole blood oxygen affinity in sickle cell anemia, and have documented that the position and shape of the oxygen dissociation curve of sickle cell blood is dependent on the time that the blood has been held in the deoxy-configuration before oxygenation, the time after venipuncture, the temperature of the sample, and whether the dissociation curve is measured in ascending or descending fashion. Only under very special conditions is the measured value related to the in vivo oxygen transport capability of blood. The pulmonary function of a large number of sickle cell anemia patients has been studied. We feel pulmonary function is a reflection of the state of circulation in the pulmonary capillary bed. These studies suggest that abnormal oxygen transport in sickle cell anemia patients is probably the result of blood abnormalities rather than specific lung disease.